Non-FDG PET/CT imaging of inflammatory arthritis

Inflammatory arthritis represents a frequent cause of disability among adults, with a huge worldwide negative societal impact. Although clinical and laboratory evaluation of patients with inflammatory arthritis still constitutes the basis of management for these patients, conventional medical imaging has traditionally provided an important aid in the assessment of these conditions. There is a pressing need to obtain an independent, objective, and reproducible imaging evaluation to support the diagnosis of disorders that are difficult to assess or determine response to an increasing number of frequently expensive treatment modalities. This could provide personalized precision medical care, tailored to the specific clinical needs of each patient. Although there has been an early recognition of the potential role that FDG-PET/CT could play in the evaluation of inflammatory or infectious disorders, its clinical introduction has been very slow, in part because approval for reimbursement did not happen until 2021. Nevertheless, there are many publications demonstrating the clinical benefit of PET imaging with FDG and other PET radiopharmaceuticals in the management of these patients. In this narrative review, we will describe the potential applications of non-FDG PET/CT imaging to assess different aspects of the complex inflammatory cascade present in inflammatory arthritis, as well as new technical developments.